1. Field of the Invention
This invention relates to polyurethane solutions and dispersions, their preparation, and the use thereof. More particularly, this invention relates to polyurethane solutions or dispersions useful as polyurethane coatings prepared from a solvent or dispersion of the reaction products of a polyester or a polyether, a hydroxyl compound having acetylenic or ethylenic unsaturation, and an organic polyisocyanate.
2. Description of the Prior Art
Solutions or dispersions of polyurethanes manufactured from hydroxyl group-containing polyesters and isocyanates employed for the manufacture of coatings or wire lacquers are known from the prior art (German Application No. 17 29 201 and German Published Application No. 25 37 207).
All of these polyurethane coatings have the disadvantage that they either contain free isocyanates, which are very sensitive to moisture upon storage, or they contain capping agents such as cresols, phenols, maleic esters, caprolactam, etc., which are evolved during the baking process and can create environmental hazards.
It is the purpose of this invention to prepare polyurethane solutions and/or dispersions, which are storage stable both in the organic and aqueous phase, which do not contain any environmentally hazardous capping agents, and which are suitable as multiple-use coating agents.